Memory system performing incremental merge operation and data write method

Abstract

A method of executing a write operation in a nonvolatile memory system includes receiving a write command indicating the write operation and write data associated with the write operation, and determining a selected merge size for use by a merge operation responsive to the write command by determining a number of free blocks and then determining a selected free block level (FBL) from among a plurality of FBLs in accordance with the number of free blocks.

What is claimed is: 
     
       1. A memory system comprising:
 a nonvolatile memory device including a plurality of memory blocks; and 
 a memory controller configured to perform an incremental merge operation in response to a write command, 
 wherein the memory controller is configured to adjust a merge size or a merge execution time adaptively in accordance with a number of free blocks among the plurality of memory blocks and a write pattern of write-requested data, and to skip the incremental merge operation during a command process cycle when the number of free blocks is over a reference number and the write pattern is a sequential write pattern. 
 
     
     
       2. The memory system of  claim 1 , wherein when the number of free blocks is the same or over the reference number, the memory controller is configured to execute the incremental merge operation during a command process cycle corresponding to a random write pattern. 
     
     
       3. The memory system of  claim 1 , wherein when the number of free blocks is below the reference number, the memory controller is configured to execute the incremental merge operation according to an adjusted merge size based on the number of free blocks, regardless of the write pattern. 
     
     
       4. The memory system of  claim 1 , wherein the memory controller is further configured to adjust the merge size adaptively according to a number of bad blocks included in the nonvolatile memory device. 
     
     
       5. The memory system of  claim 1 , wherein the incremental merge operation corresponds to an operation wherein part of a full merge operation associated with the merge size is executed during a single command process cycle. 
     
     
       6. The memory system of  claim 1 , wherein the memory controller is configured to determine a free block level in accordance with the number of free blocks to determine the merge size of the incremental merge operation. 
     
     
       7. The memory system of  claim 1 , wherein at least one of the plurality of memory blocks includes a three dimensional memory array comprising a plurality of memory cells, each of the memory cells including a charge trap layer. 
     
     
       8. A method of operating a storage device including a nonvolatile memory device, comprising:
 receiving a command; 
 determining a merge size according to a current write performance of the nonvolatile memory device; 
 performing a merge operation according to the merge size, 
 wherein the performing a merge operation includes skipping the merge operation when a number of free blocks of the nonvolatile memory device is the same or over a reference number; 
 detecting whether a number of bad blocks of the nonvolatile memory device reaches a threshold value; and 
 adjusting the reference number upon determination that the number of bad blocks is over the threshold value. 
 
     
     
       9. The method of  claim 8 , wherein the merge operation is an incremental merge operation in which a part or all of a memory block of the nonvolatile memory device is merged during a command process cycle. 
     
     
       10. The method of  claim 8 , wherein the write performance includes a current number of free blocks of the nonvolatile memory device. 
     
     
       11. The method of  claim 10 , wherein when the number of free blocks is below the reference number, the merge operation according to the determined merge size is performed regardless of a write pattern of write-requested data. 
     
     
       12. The method of  claim 10 , wherein when the number of free blocks is the same or over the reference number, the merge operation is selectively executed according to a write pattern of write-requested data. 
     
     
       13. The method of  claim 12 , wherein when the number of free blocks is the same or over the reference number and the write pattern corresponds to a sequential write, the merge operation is skipped. 
     
     
       14. The method of  claim 12 , wherein when the number of free blocks is the same or over the reference number and the write pattern corresponds to a random write, the merge operation is executed according to a minimum merge size of a plurality of merge sizes. 
     
     
       15. A storage device comprising:
 a nonvolatile memory device including a plurality of memory blocks, each of the memory blocks comprises a three dimensional memory array; and 
 a memory controller configured to perform a merge operation during a command process cycle, 
 wherein the memory controller is configured to adjust a merge size or a merge execution time adaptively in accordance with a number of free blocks among the plurality of memory blocks and a write pattern of write-requested data, and 
 wherein when the write pattern corresponds to a sequential pattern and the number of free blocks is the same or over a reference number, the memory controller is configured to selectively execute the merge operation.